Apparatus comprising an abrading head

ABSTRACT

A method for controlling operation of an abrading system ( 500 ) comprises: —providing an abrading head ( 300 ), which comprises an abrading device ( 200 ) and a communication unit (MOD 1 ), —providing parameter data (PAR 1 ) associated with the abrading device ( 200 ), —storing the parameter data (PAR 1 ) into a memory (MEM 2 ) of the communication unit (MOD 1 ), —transporting the abrading head ( 300 ) to an abrading site (SITE 1 ), —electrically connecting the abrading head ( 300 ) to a driving unit ( 400 ) at the abrading site (SITE 1 ), —transferring the parameter data (PAR 1 ) from the communication unit (MOD 1 ) to the driving unit ( 400 ) at the abrading site (SITE 1 ), and —driving an electric motor (MOTOR 1 ) of the abrading device ( 200 ) with the driving unit ( 400 ) according to the parameter data (PAR 1 ).

FIELD

Some embodiments relate to a surface processing apparatus, which comprises an abrading device.

BACKGROUND

An abrading tool, e.g. a random orbital sander device may be used until it reaches the end of life. The abrading tool may exhibit low performance or a malfunction at the end of life. The abrading tool may be inspected at a service site in order to identify the fault and/or the broken parts. Worn or broken parts may be optionally replaced. The use of the abrading tool may be continued after maintenance operations. Alternatively, the abrading tool may be dismantled for recycling of the materials. A decision about performing the maintenance operations may be made based on a result of the inspection. The inspection may be time-consuming. Visual inspection may sometimes lead to an erroneous decision about performing maintenance operations.

SUMMARY

Some versions relate to a surface processing apparatus, which comprises an abrading head. Some versions relate to a method for operating the surface processing apparatus. Some versions relate to providing usage data for facilitating maintenance of the surface processing apparatus. Some versions relate to optimizing performance of the surface processing apparatus. Some versions relate to providing usage data for improving design of the surface processing apparatus.

According to an aspect, there is provided a method for controlling operation of an abrading system (500), the method comprising:

-   -   providing an abrading head (300), which comprises an abrading         device (200) and a communication unit (MOD1),     -   providing parameter data (PAR1) associated with the abrading         device (200),     -   storing the parameter data (PAR1) into a memory (MEM2) of the         communication unit (MOD1),     -   transporting the abrading head (300) to an abrading site         (SITE1),     -   electrically connecting the abrading head (300) to a driving         unit (400) at the abrading site (SITE1),     -   transferring the parameter data (PAR1) from the communication         unit (MOD1) to the driving unit (400) at the abrading site         (SITE1), and     -   driving an electric motor (MOTOR1) of the abrading device (200)         with the driving unit (400) according to the parameter data         (PAR1).

According to an aspect, there is provided an apparatus (500), which comprises an abrading head (300), the abrading head (300) comprising an abrading device (200) for abrading a surface (SRF1), wherein the abrading device (200) is connectable to a stationary driving unit (400) for driving an electric motor (MOTOR1) of the abrading device (200) with electric currents (I₁, I₂, I₃), and wherein the abrading head (300) further comprises a communication unit (MOD1) connectable to the driving unit (400) for receiving usage data (USAG1), the usage data (USAG1) comprising information about operating history of the abrading head (300).

Further aspects are defined in the claims.

FIG. 1 shows an industrial surface processing system 500, which comprises an abrading head 300 attached to a robot ROBO1. The abrading head 300 may comprise an abrading device 200 and a communication unit MOD1.

The surface SRF1 of an object OBJ1 may be processed by using the abrading head 300. The robot ROBO1 may press the abrading head 300 against the object OBJ1, and the robot ROBO1 may move the abrading head 300 according a set of instructions specified by instruction data (DATA20), so as to process the surface SRF1 of the object OBJ1 in a desired manner. A user of the processing system 500 may provide the instructions e.g. via a user interface UIF1. The abrading device 200 of the head 300 may be electrically driven by a driving unit 400.

The abrading device 200 may be used for processing one or more objects OBJ1 at the abrading site SITE1. The abrading device 200 may be used for processing a plurality of objects OBJ1. The operating lifetime of the abrading device 200 at the abrading site SITE1 may be e.g. in the range of 10 h to 10000 h.

After use, the (first) abrading head 300 may be e.g. replaced with a new (second) abrading head 300. The abrading device 200 of the new abrading head 300 may have different operating parameters, when compared with the first abrading head 300. For example, the new abrading device 200 may have higher maximum allowed speed of rotation, higher maximum allowed electric current, and/or higher maximum operating temperature. The new device-specific operating parameters may be communicated to the driving unit 400, for using the improved capabilities of the abrading device 200 of the new head 300.

The operating parameters may be communicated to the driving unit 400 by using a communication unit MOD1. The abrading head 300 may carry a communication unit MOD1. The method may comprise transferring parameter data (PAR1) from the communication unit (MOD1) of the abrading head (300) to the driving unit (400) at the abrading site (SITE1).

The system 500 may be arranged to determine usage data during operation of the system 500. The usage data may comprise a plurality of values which represent operating history of the abrading head 300. The usage data may be stored in a memory of the communication unit MOD1. After use, the abrading head 300 may be disconnected from the driving unit 400. The abrading head 300 with the communication unit MOD1 may be transported to a service site. The gathered usage data may be subsequently read from the communication unit MOD1 e.g. at the service site. The gathered usage data may be analyzed e.g. in order to make decision about performance operations. The usage data may be compared with reference data, and the method may comprise estimating a degree of wear of one or more parts of the abrading device 200 based on the comparison. One or more parts may be optionally replaced at the service site based on analysis of the usage data. Using the usage data may facilitate making a decision about the maintenance operations.

Using the surface processing system 500 may comprise transferring operating parameter data PAR1 to the driving unit 400 and/or transferring usage data USAG1 from the driving unit 400.

An external party responsible for providing the abrading device 200 may need to transfer data into the driving unit 400 and/or from the driving unit 400. The external party may be e.g. a manufacturer of the abrading device 200 or a party responsible for servicing the abrading device 200.

The external party cannot typically rely on that he would have access to the driving unit 400.

The industrial processing system 500 may or may not have a data connection to the internet and/or to an industrial communication network. The external party responsible for manufacturing and/or maintenance of the abrading device 200 cannot typically rely on having access to the driving unit 400 via the internet or via the industrial communication network. The industrial processing system 500 typically needs to operate at a high reliability. Providing an access for an external party into the industrial processing system 500 would require additional programming work and/or may degrade the reliability of the industrial processing system 500. The user of the industrial processing system 500 may be unwilling to distribute a password to an external party for providing data access to the industrial processing system 500.

The user of the industrial surface processing system 500 typically tries to minimize spending working hours to tasks which are not directly related to providing instructions for the robot and not directly related to supervising the abrading process. Using the combination of the communication unit and the abrading device may enable reliable updating and gathering of usage data with minimum contribution from the user of the industrial processing system 500. The user of the industrial processing system 500 does not need to spend working hours on optimizing the interaction between a control unit CNT20 and the abrading device 200.

The abrading device of the abrading head may comprise several components that can be considered consumables. The abrading head may be detached from the robot after a suitable time period. The detached abrading head together with the communication unit may be transported from the abrading site to a service site. The communication unit may be attached to the abrading device such that the abrading device and the communication unit may be transported and used as a combination.

The abrading head may be inspected at the service site. One or more components of the abrading device of the abrading head may be cleaned and/or replaced at the service site. The abrading head may be transported to the same abrading site or to a new abrading site after the maintenance operations. Alternatively, a completely worn abrading head may be disposed of and recycled as raw materials.

The communication unit may provide a way of gathering and transferring usage data of the abrading head. The communication unit may provide a way of communicating optimum operating parameters of the abrading head to the driving unit. The communication unit may provide a way of communicating updated program code to the driving unit.

Personal visit with a portable computer to the abrading site may be restricted, difficult, impossible and/or expensive. The communication unit may enable transfer of data to and from a driving unit located in an inaccessible abrading site.

The communication unit may provide new software and/or parameters to a driving unit which has been previously installed in an abrading site, e.g. in an industrial production facility. An older driving unit may be automatically updated to operate with a new motor. An older driving unit may be automatically updated to provide optimum performance when connected to a new abrading head.

The communication unit may initially store e.g. the following data:

-   -   identifier of the abrading head,     -   type of the abrading head,     -   operating parameters of the motor,     -   program code for driving the inverter,     -   program code for analyzing data,

Usage data formed during operation of the abrading head may be stored into the communication unit. The usage data may comprise e.g. the following data:

-   -   total duration of operation (when the motor is rotating),     -   total number of starts (of rotation),     -   duty cycle (e.g. the ratio of on time to the off time),     -   information about temporal distribution of load, e.g. duration         of operation under heavy load, duration of operation under         medium load, and/or duration of operation under light load,     -   information about temporal distribution of operating         temperature, e.g. duration of operation at high temperature,         duration of operation at medium temperature, and/or duration of         operation at low temperature,     -   information about a maximum operating temperature of the         abrading head,     -   information about a minimum operating temperature of the         abrading head,     -   information about temporal distribution of speed of rotation,         e.g. duration of operation at high speed of rotation, duration         of operation at medium speed of rotation, and/or duration of         operation at low speed of rotation.

The method may comprise classifying an operating time period into one of a plurality of load categories based on current values measured during said operating time period.

The method may comprise classifying an operating time period into one of a plurality of temperature categories based on an operating temperature measured during said operating time period.

The method may comprise classifying an operating time period into one of a plurality of speed categories based on speed of rotation during said operating time period.

In an embodiment, the driving unit may be capable of driving the abrading head or an abrading device also in a situation where the communication unit is missing or in a situation where updating of the operating parameters is not successful. The driving unit may be configured to use e.g. a default set of operating parameters in a situation where new operating parameters are not available.

However, using the updated operating parameters may be needed in order to provide optimum and/or maximum performance of the abrading head.

The method may comprise:

-   -   providing parameter data PAR1 associated with the abrading         device 200 of the abrading head 300,     -   storing the parameter data PAR1 into a memory MEM2 of the         communication unit MOD1,     -   transporting the abrading head 300 with the communication unit         MOD1 to an abrading site SITE1,     -   electrically connecting the abrading head 300 to a driving unit         400 at the abrading site SITE1,     -   transferring the parameter data PAR1 from the communication unit         MOD1 to the driving unit 400 at the abrading site SITE1, and     -   driving the electric motor MOTOR1 of the abrading head 300 with         the driving unit 400 according to the parameter data PAR1.

The abrading head 300 may comprise an abrading device 200 for abrading a surface SRF1, and a communication unit MOD1 attached to the abrading device 200. The abrading device 200 may be connectable to a stationary driving unit 400 in order to receive driving currents from the driving unit 400. The communication unit MOD1 may be connectable to the driving unit 400 e.g. in order to receive usage data USAG1 from the driving unit 400, the usage data USAG1 comprising information about operating history of the abrading device 200.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following examples, several variations will be described in more detail with reference to the appended drawings, in which

FIG. 1 shows, by way of example, an abrading apparatus at an abrading site,

FIG. 2 a shows, by way of example, in a cross-sectional view, an abrading head,

FIG. 2 b shows, by way of example, in a cross-sectional view, an abrading device of the abrading head,

FIG. 2 c shows, by way of example, in a cross-sectional view, a motor assembly of the abrading device,

FIG. 2 d shows, by way of example, a communication unit of the abrading head,

FIG. 3 shows, by way of example, a driving unit for driving the abrading head,

FIG. 4 shows, by way of example, a communication unit of the abrading head,

FIG. 5 shows, by way of example, reading usage data from the communication unit at a service site,

FIG. 6 a shows, by way of example, method steps for updating the abrading apparatus, forming usage data indicative of operating history of the abrading apparatus, and storing the usage data into the communication unit,

FIG. 6 b shows, by way of example, method steps for determining an end of life indicator,

FIG. 7 shows, by way of example, a system for designing, producing, and using abrading heads,

FIG. 8 a shows, by way of example, an indicator unit for providing an end of life indication to a user,

FIG. 8 b shows, by way of example, a communication unit which comprises data processing capabilities,

FIG. 9 shows, by way of example, temporal evolution of speed, current and temperature of the motor,

FIG. 10 a shows, by way of example, operating parameters for driving the abrading head,

FIG. 10 b shows, by way of example, usage parameters, and

FIG. 11 shows, by way of example, collecting sensor data from one or more auxiliary sensors.

DETAILED DESCRIPTION

Referring to FIG. 1 , an abrading apparatus 500 may comprise an abrading head 300 attached to an actuator ROBO1. The actuator ROBO1 may be e.g. move the abrading head 300 in one or more dimensions with respect to the object OBJ1, and/or the actuator ROBO1 may change angular orientation of the abrading head 300 with respect to the object OBJ1. The actuator ROBO1 may change the position and/or orientation of the abrading head 300 with respect to the object OBJ1. The actuator ROBO1 may be e.g. an industrial robot. The actuator ROBO1 may be e.g. a collaborative robot.

The apparatus 500 may be arranged to process a surface SRF1 of the object OBJ1 by abrading. The abrading head 300 may comprise an abrading device 200. The term abrading may include e.g. grinding, sanding, polishing and/or honing. The abrading device 200 may be e.g. a random orbital sander device. The abrading device 200 may comprise an electric motor MOTOR1, which is connected to a driving unit 400. The driving unit 400 may provide electric currents for driving the electric motor MOTOR1 at a selected speed of rotation. The driving unit 400 may drive the electric motor MOTOR1 at an adjustable speed of rotation.

The robot and the abrading head may be controlled by a control unit CNT20 of a production system 500, according to the instructions specified in the instruction data DATA20. The control unit CNT20 may be configured to perform processing operations specified in the in the instruction data DATA20 by executing program code PROG20. The control unit CNT20 may be configured to operate the abrading device 200 according to operating parameters specified in parameter data PAR1. The production system 500 may comprise a memory MEM21 for storing program code PROG2, a memory MEM22 for storing instruction data DATA20, and a memory MEM23 for storing operating parameter data PAR1. The parameter data PAR1 may define values for driving the motor of the abrading device 200. The parameter data PAR1 may e.g. specify one or more of the following values: maximum speed of rotation of the motor, maximum average current of the motor, maximum instantaneous current of the motor, maximum rate of change of speed of rotation, maximum operating temperature of the motor.

The object OBJ1 may be a product. The object OBJ1 may be e.g. a part of a vehicle, a part of a boat, an element of a building, or a part of an airplane. The material of the surface SRF1 may comprise e.g. wood, metal, polymer and/or ceramic material. The surface SRF1 may be processed with the abrading head 300 e.g. before or after applying a layer of paint. The surface SRF1 may be processed by using the abrading head 300 e.g. before or after applying a layer of coating material. The abrading head 300 may e.g. polish the surface or remove rust from the surface SRF1. The abrading head 300 may be e.g. an orbital sander. The abrading head 300 may be e.g. a random orbital sander.

The production system may comprise a user interface UIF1 for receiving user input from a (human) user of the robot. The user interface UIF1 may comprise e.g. a display, a keyboard, a joystick and/or or a touchscreen. The user may e.g. provide user input for forming processing instructions specified in the instruction data DATA20. In an embodiment, the user interface UIF1 may also comprise the robot, i.e. the user may manually move the robot in order to teach desired movements to the processing system 500.

In an embodiment, the user may provide user input also in substantially real time for controlling operation of an industrial robot or for controlling operation of a collaborative robot.

The processing system 500 may comprise a driving unit 400 to drive the abrading head according to control signals received from the control unit CNT20. The driving unit 400 may be connected to the abrading head by an electric cable CON1. The electric cable CON1 may conduct electric currents to the motor of the abrading head.

The processing system 500 may comprise a robot driving unit DU2 to drive the robot ROBO1 according to control signals received from the control unit CNT20.

The control unit CNT20 may or may not be capable of receiving data from an external computer e.g. via the Internet and/or via an industrial data network.

The abrading head may comprise the abrading device and the communication device. The communication unit may be mechanically attached to the abrading device so that the abrading device and the communication unit may be transported and used as a combination. The communication unit may be combined with the abrading device. The method may comprise forming a combination of the communication unit and the abrading device.

The communication unit may comprise e.g. a printed circuit board and/or an integrated circuit implemented on a semiconductor chip.

The abrading head may be attached e.g. to a robot. The robot may move the abrading head in order to process the surface of an object.

The abrading head may be connected to an external driving unit. The driving unit may provide electric currents at an adjustable frequency, so as to drive the electric motor of the abrading head at a selected speed of rotation. The external driving unit may be located e.g. in a cabinet or in a box at an abrading site close to the robot. The external driving unit may be stationary.

The abrading head 300 may be connected to the external driving unit 400 via an electric cable CON1, so as to feed driving electric currents I₁, I₂, I₃ to the motor MOTOR1 of the abrading head 300. The distance between the abrading head 300 and the driving unit 400 may be. e.g. greater than 0.5 m during operation. The distance between the abrading head 300 and the external driving unit 400 may be. e.g. in the range of 0.5 m to 20 m during operation.

The external driving unit 400 may be arranged to operate in a relatively dust-free environment. The external driving unit 400 may be arranged to operate in a relatively vibration-free environment. The external driving unit 400 may be arranged to operate at normal ambient temperature. When using the external driving unit 400, the weight and/or the size of the abrading head 300 may be reduced. Thus, the robot ROBO1 may move the abrading head 300 faster or by using a smaller force.

The abrading head may be implemented e.g. such that it does not comprise e.g. handle and/or a switch for manual operation. The amplitude of vibration of the abrading head may be too large for manual (handheld) operation. The abrading head may be implemented such that it is unsuitable for manual (handheld) operation.

The abrading head may also be called e.g. as an abrading tool.

In an embodiment, a stationary abrading head 300 may be connected to a stationary driving unit 400. An actuator ROBO1 may be arranged to move the object OBJ1 with respect to the abrading head 300. The distance between the abrading head 300 and the driving unit 400 may be. e.g. greater than 0.5 m. Also in this case, the driving unit 400 may operate in a substantially dust-free and vibration-free environment, at normal ambient temperature.

Referring to FIG. 2 a , the abrading head 300 may comprise an abrading device 200 and a communication unit MOD1.

Referring to FIGS. 2 b and 2 c , the abrading device 200 may comprise an electric motor MOTOR1 to cause oscillation and/or rotation of an abrasive element ABR1. The abrading device 200 may comprise an eccentric pivot mechanism ECC1 to convert a rotary motion of the motor MOTOR1 into an oscillatory motion of the abrasive element ABR1. The abrading device 200 may comprise a rotating and/or oscillating support element PAD1 to hold the abrasive element ABR1. The pivot mechanism ECC1 may cause oscillation of the support element PAD1.

The motor MOTOR1 may be a synchronous electric motor. The motor MOTOR1 may be a brushless synchronous electric motor. The motor MOTOR1 may comprise a rotating rotor ROTO1, a non-rotating stator STAT1, and one or more bearings BEA1 a, BEA1 b. The rotor and/or the stator may comprise a plurality of coils to receive electric driving currents from the driving unit 400. The driving unit 400 may provide electric driving alternating currents which have a suitable phase and frequency so as to cause rotation of the motor at a desired speed of rotation. The electric currents may be fed to the motor e.g. via a connector C3 a.

The motor may also comprise permanent magnets to generate electromagnetic forces together with the coils, so as to cause rotation of the rotor.

The abrading device 200 may optionally comprise one or more counterweights for reducing vibration of the motor. The abrading device 200 may comprise a balanced eccentric pivot. The pivot mechanism ECC1 may comprise one or more counterweights for reducing internal forces and vibration. A shaft 240 of the motor may be balanced to reduce internal forces and vibration.

The abrading device 200 may optionally comprise one or more fans for causing an air flow for cooling the motor. The abrading device 200 may optionally comprise one or more fans for causing an air flow for removing dust particles. The abrading device 200 may optionally comprise a first fan for cooling and a second fan for removing dust.

Processing a surface SRF1 with the abrasive element ABR1 may release material particles from the surface SRF1 and abrasive particles from the abrasive element ABR1. The abrading device 200 may comprise one or more seals SEAL1, SEAL2 to reduce wear caused by the released particles.

The abrading device 200 may have a limited operating lifetime. For example, bearings, seals, and/or the support element may wear during operation. For example, electric insulation of the coils may be damaged due to operation at high temperature. For example, the motor shaft, the eccentric pivot and/or a clutch system may be damaged due to fatigue cracking. The operating lifetime may e.g. depend on one or more of the following operating parameters: operating temperature of the motor, operating temperature of the bearings, grinding pressure, electric current, torque, speed of rotation, number of starts, weight of the oscillating parts.

The motor and the bearings may generate heat during operation. The abrading head 300 may comprise a temperature sensor TC1 for monitoring an operating temperature of the abrading head 300. In particular, the temperature sensor TC1 may monitor operating temperature of the motor MOTOR1. The temperature sensor TC1 may be e.g. a thermistor or a thermocouple. The temperature sensor TC1 may provide an analog or a digital temperature signal (S2). The temperature signal may be transferred from the abrading head 300 to the driving unit 400 e.g. via electric wires and/or via a connector C2 a.

The temperature signal (S2) may be transferred from the abrading head 300 to the driving unit 400 in analog form. The driving unit 400 may comprise a temperature reader to convert the analog temperature signal into digital form.

The abrasive element ABR1 and the support element PAD1 may comprise one or more openings for removing the released particles together with an air flow AIR1. The abrasive element ABR1 and the support element PAD1 may define one or more ducts DUC2 for removing the released particles together with an air flow AIR1.

The abrading device 200 may comprise one or more flow guiding elements 250 to guide an air flow AIR1 near the casing 210 of the motor MOTOR1, so as to cool the motor MOTOR1. The abrading device 200 may define one or more ducts DUC1 for air flow AIR1, so as to cool the motor MOTOR1.

The abrading device 200 may comprise a suction port 252, which is connectable to suction system, so as to suck air and released particles from the abrading device 200. The suction system may cause a partial vacuum, which may draw air and released particles from the abrading device 200. The suction port 252 may be in fluid connection with the particle-removing ducts DUC2 and/or with the cooling ducts DUC1. The suction port 252 may be connected e.g. to a dust suction device e.g. via a flexible hose.

The abrading device 200 may comprise means REL1 for holding an abrasive element ABR1. The abrading device 200 may comprise a rotating and/or oscillating support element PAD1 to hold an abrasive element ABR1. The abrasive element ABR1 may be e.g. an abrasive disc or plate, which comprises abrasive grains. The grit size of the abrasive grains may be e.g. in the range of 40 to 1200. The abrasive element ABR1 may be releasably attached the support element PAD1. The abrasive element ABR1 may be attached the support element PAD1 e.g. by hook and loop fasteners (REL1). The abrasive element ABR1 may be attached the support element PAD1 e.g. by pressure sensitive adhesive.

The abrading device 200 may be a random orbit abrading device, which may be arranged to cause orbital oscillation of the abrasive element ABR1. The motor MOTOR1 may have a first axis AX1 of rotation. The support element PAD1 may be eccentrically pivoted to the shaft of the motor MOTOR1 by one or more bearings BEA2. The pivot point may have a pivot axis AX2. The displacement e1 between the axis AX1 and the pivot axis AX2 may be e.g. in the range of 0.5 mm to 20 mm, typically in the range of 1.25 to 6 mm. Each abrasive grain of the abrasive element ABR1 may move along a substantially circular orbit, which has a diameter of two times the displacement value e1.

The random orbit abrading device 200 may comprise a one or more braking elements to prevent free rotation of the support element PAD1 during eccentric oscillation of the support element PAD1. The random orbit abrading device 200 may comprise one or more braking elements to slow down or prevent rotation of the support element PAD1. For example, the abrading device 200 may comprise a clutch mechanism to prevent rotation of the support element PAD1, while allowing the orbital oscillation. The clutch mechanism may comprise e.g. a resilient belt to prevent rotation of the support element PAD1.

The abrading device 200 may comprise e.g. a braking seal SEAL3, which may be e.g. an annular element positioned between a housing 260 of the device 200 and a peripheral portion of the support element PAD1. The braking seal SEAL3 may allow oscillation of the support element PAD1 while preventing free rotation of the support element PAD1. The braking seal SEAL3 may prevent free rotation of the support element PAD1 by causing friction. The braking seal SEAL3 may also reduce leakage of air.

The random orbit abrading device 200 may be arranged to operate such that speed of rotation of the abrasive element ABR1 is e.g. smaller than 10% of the speed of rotation of the motor MOTOR1 during oscillation of the abrasive element ABR1. The random orbit abrading device 200 may be arranged to operate such that speed of rotation of the support element PAD1 is e.g. smaller than 10% of the speed of rotation of the motor MOTOR1 during oscillation of the support element PAD1.

In an embodiment, the support element PAD1 of the abrading device 200 may also be arranged to rotate freely during the forced eccentric oscillation.

The braking mechanism for preventing the free rotation may also be omitted e.g. when the abrasive element ABR1 is pressed against the object OBJ1 before starting the rotation of the motor.

The abrading head 300 may comprise one or more attachment elements (SUP1), which may be attached to the robot ROBO1. The attachment element SUP1 may be e.g. a flange with threads or holes (OP1), which may allow attaching the abrading head 300 to the robot e.g. by screws.

The abrading head 300 may also be fastened to the robot via an auxiliary fastening element. The attachment element SUP1 may allow attaching the abrading head 300 to the fastening element of a tool changing mechanism.

The fastening element may, in turn, be rapidly, automatically, and removably fastened to the robot.

In an embodiment, the abrading head 300 may also be stationary, wherein the object OBJ1 may be moved by using an actuator (e.g. ROBO1).

The communication unit MOD1 may be e.g. attached to the abrading device 200 so that the communication unit MOD1 and the abrading device 200 may be transported as a combination.

Data (PAR1, PROG1, USAG1) may be sent e.g. via electric wires between the communication unit MOD1 and the driving unit 400. Data (PAR1, PROG1, USAG1) may be sent e.g. by serial communication via electric wires between the communication unit MOD1 and the driving unit 400. Data may be transferred from the communication unit MOD1 and to the communication unit MOD1 e.g. via a connector C1 a. The connector C1 a may enable e.g. serial communication. The connectors C1 a, C2 a, C3 a may be separate connectors, or the connectors C1 a, C2 a, and/or C3 a may be connector portions of the same connector. Each driving current of the motor may also be connected by a separate (1-pole) connector.

The abrading device 200 may optionally comprise a fan for causing an air flow for cooling the motor. Using a separate fan for cooling and drawing removed particles to a suction system may provide efficient removal of the particles and/or may allow reducing the power of the suction system.

FIG. 2 d shows, by way of example, a communication unit MOD1.

Referring to FIG. 3 , the processing system 500 may comprise a stationary driving unit 400 located at an abrading site SITE1.

The driving unit 400 may comprise an inverter unit DRV1 to provide electric currents I₁, I₂, I₃ to the coils of the motor of the abrading head 300, at a desired phase and frequency. The inverter unit DRV1 may provide electric currents for driving a synchronous motor, which has three or more pole pairs. The motor may have e.g. three pole pairs. The motor may have e.g. four pole pairs. The inverter unit DRV1 may comprise e.g. power transistors to provide the electric currents for driving the synchronous motor. The electric currents may be conducted to the motor via wires W1, W2, W3. The electric currents (I₁, I₂, I₃) for driving the motor may be provided e.g. via three or more conductors W1, W2, W3, e.g. according to the number of the pole pairs of the motor.

The driving unit 200 may comprise a current meter unit SEN1 to monitor the magnitude of the electric currents of the motor MOTOR1.

The driving unit 200 may comprise a temperature sensor reader READ1 to convert an analog temperature signal (S2) into digital form.

The driving unit 400 may comprise a first communication interface COM1 b for receiving data (PAR1, PROG1) from the communication unit MOD1 to the driving unit 400 and/or for transmitting usage data (USAG1) from the driving unit 400 to the communication unit MOD1.

The communication unit MOD1 may send operating parameter data PAR1 to the driving unit 400. The operating parameter data PAR1 may be stored in a memory of the driving unit 400. The driving unit 400 may control operation of the inverter unit DRV1 according to the operating parameter data PAR1. The operating parameter data PAR1 may e.g. specify maximum allowed rotation speed, maximum current value for the motor currents and/or maximum operating temperature of the abrading head.

The driving unit 400 may comprise a second communication interface COM2 b for receiving operating instructions S1 from the robot control unit CNT20. The driving unit 400 may be connected to the robot control system e.g. via a connector C20. An operating instruction S1 may e.g. command the driving unit 400 to start operation at maximum speed of rotation, or to stop rotation. An operating instruction S1 may e.g. specify a target speed of rotation. The driving unit 400 may execute a received command according to the operating parameter data PAR1. For example, the driving unit 400 may drive the motor only at the maximum speed of rotation in a situation where the instructed target speed of rotation is higher than the maximum allowed speed of rotation.

The apparatus 500 may be arranged to monitor operating temperature of the abrading head and/or to monitor electric currents of the motor. The driving unit 400 may also gather information about the start times, stop times and speed of rotation of the motor. The driving unit 400 may comprise a clock CLK1 to provide time data. The driving unit 400 may associate gathered data with time so as to provide time stamped data.

The driving unit 400 may be configured to analyze the gathered temperature data, electric current data, and rotation speed data, so as to form usage data USAG1. The usage data USAG1 may represent operating history of the abrading head 300. The usage data USAG1 may represent operating history of the abrading head 300 in a compressed form. The driving unit 400 may be configured to form usage data from the gathered temperature data, electric current data, rotation speed data, and time data. The driving unit 400 may be configured to form usage data from the gathered temperature data, electric current data, rotation speed data, and time data according to method steps specified by the program code PROG1.

The formed usage data USAG1 may comprise e.g. the following data:

-   -   total duration of operation (when the motor is rotating),     -   total number of starts (of rotation),     -   duty cycle (e.g. the ratio of on time to the off time),     -   information about temporal distribution of load, e.g. duration         of operation under heavy load, duration of operation under         medium load, and/or duration of operation under light load,     -   information about temporal distribution of operating         temperature, e.g. duration of operation at high temperature,         duration of operation at medium temperature, and/or duration of         operation at low temperature,     -   information about a maximum operating temperature of the         abrading head,     -   information about a minimum operating temperature of the         abrading head,     -   information about temporal distribution of speed of rotation,         e.g. duration of operation at high speed of rotation, duration         of operation at medium speed of rotation, and/or duration of         operation at low speed of rotation.

The method may comprise classifying an operating time period into one of a plurality of load categories based on current values measured during said operating time period.

The method may comprise classifying an operating time period into one of a plurality of temperature categories based on an operating temperature measured during said operating time period.

The method may comprise classifying an operating time period into one of a plurality of speed categories based on speed of rotation during said operating time period.

The driving unit 400 may be configured to analyze the gathered temperature data, electric current data, and rotation speed data. The driving unit 400 may be configured to determine an end of life indicator IND1 from the gathered data according to an algorithm defined by program code PROG1. The end of life indicator IND1 may be indicative of an estimated remaining lifetime of the abrading head. For example, the end of life indicator IND1 may indicate a low remaining lifetime e.g. in a situation where the abrading head has been running at full speed over 1000 hours, and the operating temperature has not exceeded a predetermined temperature limit. For example, the end of life indicator IND1 may indicate a low lifetime e.g. in a situation where the abrading head has been running at maximum temperature over 10 hours. For example, the end of life indicator IND1 may indicate a long remaining lifetime in a situation where the abrading head has been operating less than 10 hours and the operating temperature has never exceeded the predetermined temperature limit.

The end of life indicator IND1 may be communicated to the robot control unit CNT20, e.g. if requested by the robot control unit CNT20. The robot control unit CNT20 may optionally provide an alarm indication e.g. via the user interface UIF1, in a situation where an estimated remaining lifetime of the abrading head 300 is lower than a predetermined value. In that case the user of the processing system 500 may e.g. send a request to the external party to replace the abrading head 300, well in advance before the abrading head 300 exhibits a serious failure or inferior performance.

The abrading head 300 may optionally comprise an indicator unit LED1 to provide an indication to the user about a low remaining lifetime (FIG. 8 a ). The indicator unit LED1 may provide e.g. an optical signal and/or an audio signal. The indicator unit LED1 may comprise e.g. a light emitting diode, which may be arranged to emit pulsed light signal in a situation where the estimated remaining lifetime is low.

The program code PROG1 specifying the algorithm for forming the usage data USAG1 and/or specifying the algorithm for determining the end of life indicator IND1 may be received from the communication unit to the driving unit 400. A user of the processing system 500 may initiate transfer of data PAR1, PROG1 e.g. by using the user interface UIF1. The system 500 may send a command or permission to the driving unit 400 e.g. via the communication interface COM2 b, so as to initiate transfer of data PAR1, PROG1. The driving unit 400 and/or the communication unit MOD1 may also be arranged to initiate transfer of the data when the communication unit MOD1 is connected to the driving unit 400. The communication unit or the driving unit may initiate the communication of data, e.g. in a situation where the communication unit is connected to a driving unit.

The driving unit 400 and/or the communication unit may also comprise e.g. a manual switch to initiate transfer of the data. The system 500 may check whether data transfer is successful e.g. by using checksum verification.

A research and development team of a manufacturer of the abrading head 300 may gather usage data from several abrading heads. The team may determine an improved model for predicting the remaining lifetime of the abrading head, based on the measured operating parameters. The team may form an improved algorithm for determining the end of life indicator, based on the gathered usage data. The lifetime of a driving unit 400 may be e.g. greater than 10 years. The end of life algorithm stored in a memory of the driving unit 400 may also be changed one or more times during the lifetime of the driving unit 400, by transferring new program code PROG1 to the driving unit 400.

The driving unit 400 may comprise one or more data processors CNT1 to process operating data e.g. according to the program code PROG1.

The driving unit 400 may comprise one or more data processors CNT1 to determine usage data USAG1 from the operating data by executing the program code PROG1.

The driving unit 400 may comprise one or more data processors CNT1 for determining the end of life indicator IND1 from the measured operating data, by executing the program code PROG1.

The communication unit MOD1 may comprise one or more data processors for determining usage data USAG1 from the operating data OPDATA1 by executing the program code PROG1.

The communication unit MOD1 may comprise one or more data processors for determining the end of life indicator IND1 from the operating data OPDATA1 by executing program code PROG1.

The driving unit 400 may comprise one or more connectors C1 b, C2 b, C3 b to mate with one or more corresponding connectors (e.g. C1 a, C2 a, C3 a).

The driving currents (I₁, I₂, I₃) may be conducted from the driving unit 400 to the motor MOTOR1 via an electric cable (CON1). The cable CON1 may also comprise one or more wires for transferring the parameter data PAR1 and/or for transferring usage data USAG1. The connecting cable CON1 may comprise one or more connectors C1 a, C2 a, C3 a to mate with the one or more connectors C1 b, C2 b, C3 b.

The system 500 may optionally comprise one or more additional cables for transferring data (PAR1, USAG1).

The driving unit 400 may comprise one or more sensors TC2 for monitoring operating temperature of the driving unit 400. The driving unit 400 may comprise e.g. a sensor TC2 for monitoring operating temperature of a component of the inverter DRV1. The component may be e.g. a power transistor.

Referring to FIG. 4 , the communication unit MOD1 may comprise a communication interface COM1 a to enable transfer of data to the driving unit 400 and from the driving unit 400. The communication unit MOD1 may be connected to the driving unit 400 e.g. via a connector C1 a.

The communication unit MOD1 may comprise a memory MEM1 for storing program code PROG1, a memory MEM2 for storing operating parameters PAR1, and a memory MEM3 for storing usage data USAG1.

The abrading head 300 may be used for processing objects e.g. during a predetermined time period, or until the end of life indicator indicates that the remaining lifetime is low. The abrading head 300 may be subsequently detached from the robot ROBO1, and the abrading head 300 may be disconnected from the driving unit 400 for transporting it to a service site SITE2. The abrading device 200 with the communication unit MOD1 may be transported as a combination from the abrading site SITE1 to a service site SITE2.

The unit MOD1 may be attached to the abrading device 200 e.g. by one or more screws. The unit MOD1 may be attached to the abrading device 200 e.g. by clamping. The unit MOD1 may be attached to the abrading device 200 e.g. by an adhesive joint. The unit MOD1 may be in mechanical contact with the abrading device 200.

The communication unit MOD1 may comprise one or more circuit boards and/or semiconductor chips. The unit MOD1 may optionally comprise a housing 310 e.g. to protect the unit MOD1 from dust. The communication unit MOD1 may e.g. a communication module. The communication module MOD1 may be e.g. attached to the abrading device 200.

The communication unit MOD1 may be located e.g. inside or outside the casing 210 of the motor MOTOR1. Positioning the unit MOD1 inside the casing 210 of the motor MOTOR1 may e.g. protect the unit MOD1 from dust and/or from contact with external objects.

The communication unit MOD1 may be combined with the abrading device 200 also by integrating the communication unit MOD1 into the abrading device 200.

The abrading head 300 may comprise a communication unit MOD1, which has been integrated into the abrading device 200.

The communication unit MOD1 may optionally provide one or more auxiliary functionalities to facilitate operation of the abrading head 300. For example, the unit MOD1 may comprise a temperature sensor (e.g. the sensor TC1) for monitoring operating temperature of the motor MOTOR1. The unit MOD1 may comprise e.g. a temperature reader (READ1) to convert an analog temperature signal (S2) of a temperature sensor into digital form. The unit MOD1 may comprise one or more parts of a temperature monitoring system. The unit MOD1 may comprise a position sensor for detecting angular orientation of the rotor ROTO1. The unit MOD1 may comprise one or more parts of a position sensor system for detecting angular orientation of the rotor ROTO1. The position sensor may be e.g. a rotary encoder.

In an embodiment, the communication unit may comprise a circular buffer memory (MEM3) for storing usage data. The usage data stored in the communication unit may be read e.g. for end of life diagnostics, in a situation where an abrading head has been detached from the abrading system due to malfunction or due to low performance. In an embodiment, the circular buffer memory may be arranged to store usage data which represents e.g. the last few hours of operation of the abrading head, before a severe malfunction, at a high temporal resolution.

Referring to FIG. 5 , the communication unit MOD1 may be connected to a computer PC1 at the service site SITE2. The usage data USAG1 may be read from the memory MEM3 of the communication unit MOD1 e.g. to a computer PC1 at the service site SITE2. Usage data USAG1 may be read from the communication unit MOD1 at a service site SITE2 e.g. by using serial port communication. The data may be communicated e.g. via connectors C1 a, C1 c. In an embodiment, data may be read from the communication unit also by wireless communication, e.g. by near field communication (NFC).

The usage data USAG1 read from the communication unit MOD1 may be subsequently communicated e.g. to an internet server 1260, and/or to one or more other computers 1240, 1250. The data may be communicated e.g. via a communication network 1220, e.g. via the Internet. The symbols 1201, 1230, 1241, 1251 may denote data links.

The usage data USAG1 may be e.g. analyzed at a development site SITE3. The design of new abrading heads 300 may be modified and/or optimized based on the analysis. The design of new abrading heads 300 may be modified based on the analysis e.g. in order to increase lifetime, to improve one or more operating parameters, and/or in order to decrease manufacturing costs.

FIG. 6 a shows, by way of example, method steps for updating parameter data and gathering usage data.

Parameter values specifying the maximum performance of an abrading head 300 may be stored in the communication unit MOD1 in step 1110. The Parameter values PAR1 may be stored to the communication unit MOD1 e.g. at a production site (SITE4) or at a service site (SITE2).

The abrading head 300 may be transported to an abrading site SITE1 in step 1115.

The abrading head 300 may be connected to a stationary driving unit 400 at the abrading site SITE1 in step 1120.

The new parameter values PAR1 may be transferred from the communication unit MOD1 to the driving unit 400 in step 1125.

The abrading head 300 may be operated according to the new parameter values PAR1 in step 1130.

The usage data USAG1 may be formed from the measured temperature, current, rotation speed and time data in step 1135.

The usage data USAG1 may be stored into the communication unit MOD1 in step 1140. The usage data USAG1 may be formed and stored at regular or irregular intervals during operation of the abrading head 300, e.g. in order to ensure that stored usage data USAG1 is available also after a situation where the abrading head 300 or the driving unit 400 suddenly stops operation e.g. due to severe malfunction. The communication unit MOD1 may comprise e.g. a circular buffer memory (MEM3) to ensure that sufficient memory space is always available to store usage data USAG1, for determining what happened during the last minutes before a severe malfunction.

The abrading head 300 and the communication unit MOD1 may be disconnected from the driving unit 400.

The abrading head 300 together with the communication unit MOD1 may be transported from the abrading site SITE1 to a second site SITE2 in step 1180. The geographical distance between the abrading site SITE1 and the second site SITE2 may be e.g. greater than 1 km. The second site SITE2 may be e.g. service site.

The usage data USAG1 may be read from the communication unit MOD1 in step 1185, e.g. at the second site SITE2.

One or more service operations may be optionally performed in step 1190. For example, a motor and/or a bearing may be replaced at the service site SITE2. In an embodiment, the degree of wear of a component is determined by analyzing the usage data USAG1. One or more service operations may be performed based on analysis of the usage data. In an embodiment, the method comprises determining whether a component of the abrading head 300 needs to be replaced or not based on analysis of the usage data USAG1 read from the communication unit of the abrading head.

FIG. 6 b shows, by way of example, method steps for updating program code of the driving unit.

Program code PROG1 may be stored in the communication unit MOD1 in step 1112, e.g. at a service site SITE2 or at a production site (SITE4).

The abrading head 300 may be transported to the abrading site SITE1 in step 1115.

The abrading head 300 may be connected to the driving unit 400 at the abrading site SITE1 in step 1120.

The program code PROG1 may be transferred from the communication unit MOD1 to the driving unit 400 at the abrading site SITE1 in step 1127.

The abrading head 300 may be operated at the abrading site SITE1 in step 1130.

The usage data USAG1 may be formed from the measured temperature, current, rotation speed and time data in step 1135. The usage data USAG1 may be formed according to one or more algorithms specified by the program code PROG1.

End of life indicator IND1 may be determined in step 1150. A new value of the end of life indicator IND1 may be determined at regular or irregular intervals during operation of the abrading head 300. The end of life indicator IND1 may be determined according to one or more algorithms specified by the program code PROG1.

An indication may be provided according to the determined end of life indicator IND1 in step 1155. For example, the user interface UIF1 may display an alarm if the estimated remaining life is lower than a predetermined value. For example, a beacon may start flashing or change color if the estimated remaining life is lower than a predetermined value.

The abrading head 300 may be disconnected from the driving unit 400. The abrading head 300 may be transported from the abrading site SITE1 to a second site SITE2 in step 1180. The usage data USAG1 may be optionally read in step 1185 (FIG. 6 a ).

One or more service operations may be optionally performed in step 1190. One or more service operations may be performed based on analysis of the usage data.

After the visit to the second site SITE2, the abrading head 300 may be connected again to the same driving unit 400 or to a different driving unit 400, at the first site SITE1.

After the visit to the second site SITE2, the abrading head 300 may be connected to a different driving unit 400 at a different abrading site.

Referring to FIG. 7 , a production (eco)system may comprise a production site (SITE4). New abrading heads 300 and or components of abrading heads may be produced at the production site (SITE4). The abrading heads may be produced e.g. by using an assembly line. Parameter data PAR1 and/or program code PROG1 may be stored into the communication units MOD1 at the at the production site (SITE4), before transporting the abrading heads to an abrading site (SITE1).

The ecosystem may comprise a surface processing system 500 at an abrading site SITE1. An abrading head may be used for processing objects at the abrading site SITE1. The processing system 500 comprises a stationary driving unit 400 to receive commands from an industrial control system (CTN20), to control the abrading head 300, to measure operating parameters (temperature, current), and to form usage data USAG1 from the measured operating parameters (temperature, current).

The ecosystem may comprise one or more service sites SITE2. The usage data may be read from the communication unit MOD1 at the service site SITE2. One or more service operations may be performed at the service site SITE2. New (maximum allowed/recommended) operating parameters and/or new program code PROG1 may be stored to the communication units MOD1 at the service site SITE2, in a situation where the abrading head 300 is sent to an abrading site (SITE1) after maintenance operations.

The ecosystem may comprise a development site SITE3. Usage data collected from a plurality of abrading heads may be analyzed at the development site SITE3. The development site SITE3 may e.g. provide:

-   -   new program code PROG1,     -   new (maximum allowed/recommended) operating parameters,     -   determining a (customer-specific) pricing model,     -   improved design for a new abrading head,     -   design for an improved component, and/or     -   improved method for testing abrading head or component.

The development site SITE3 may communicate new parameters, code and/or design to the production site SITE4. The development site SITE3 may communicate new parameters and code to one or more service sites SITE2.

Referring to FIG. 8 a , the abrading head 300 may comprise an indicator unit LED1 to provide an indication. For example, the communication unit MOD1 may comprise a light emitting diode to provide visual indication. The apparatus may be arranged to provide indication e.g. if the end of life indicator value fulfils a predetermined criterion.

Referring to FIG. 8 b , also the communication unit MOD1 may comprise one or more data processors CNT2. For example, the communication unit MOD1 may comprise one or more data processors CNT2 to form usage data (USAG1) from gathered operating data (OPDATA1) by executing program code (PROG1).

The communication unit MOD1 may comprise one or more data processors (CNT2) for determining the end of life indicator (IND1) from the operating data (OPDATA1) by executing program code (PROG1).

The communication unit MOD1 may comprise one or more data processors (CNT2) for determining the end of life indicator IND1 from the usage data (USAG1) by executing program code (PROG1).

FIG. 9 shows, by way of example, temporal evolution of actual speed (VEL(t)) of rotation of the motor MOTOR1, temporal evolution of driving current (I_(M)(t)) of the motor MOTOR1, and temporal evolution of operating temperature (T_(M)(t)) of the motor MOTOR1. The symbol I_(M)(t) may indicate e.g. the RMS value of the current of one phase (I₁, I₂, I₃), or the average of the RMS values of the currents (I₁, I₂, I₃). RMS means root mean square.

The abrading system 500 may provide operating data OPDATA1 substantially in real time.

The operating data OPDATA1 may comprise e.g. target speed of rotation of the motor, as defined by the instructions S1. The operating data may comprise e.g. an actual speed of rotation (VEL(t)) of the motor, which may be determined e.g. from a control signal of the inverter DRV1. The actual speed of rotation may also be determined e.g. by detecting or measuring the frequency of the alternating driving currents (I₁, I₂, I₃).

The operating data OPDATA1 may comprise e.g. the magnitude (I_(M)(t)) of the electric driving currents. The electric currents may be measured e.g. by using the current meter unit SEN1.

The operating data OPDATA1 may comprise e.g. measured temperature (T_(M)(t)) of the motor MOTOR1. The temperature of the motor MOTOR1 may be measured e.g. by using the temperature sensor TC1.

The curves of FIG. 9 may represent 7 operating cycles CYC1, CYC2, . . . CYC7 of the abrading head 300. The symbols t_(1a), t_(2a), t_(3a), . . . t₇ denote start times of the motor. The symbols t_(1b), t_(2b), t_(3b), . . . t_(7b) denote stop times of the motor.

Each operating cycle CYC1, CYC2, . . . may have a duration L₁, L₂, . . . L₇ defined by a difference between the start time and the stop time of said cycle. For example, the duration L₁ of the first cycle CYC1 is equal to the difference t_(1b)-t_(1a).

The symbol LLIM1 may denote a first limit value for classifying the duration of an operating cycle. The symbol LLIM2 may denote a second limit value for classifying the duration of an operating cycle. Each cycle may be determined to belong one of several categories based on the duration. The duration of each cycle may be compared with one or more limit values LLIM1, LLIM2 in order to classify said cycle into one of several categories. The number of the different categories may be e.g. two or more. For example, a cycle may be determined to belong to the category of “short” duration if the duration of said cycle is smaller than the first limit LLIM1. For example, a cycle may be determined to belong to the category of “long” duration if the duration of said cycle is greater than the second limit LLIM2. For example, a cycle may be determined to belong to the category of “medium” duration if the duration of said cycle is between the limits LLIM1 and LLIM2.

For example, the cycle CYC1 may be classified to be a “short” cycle. For example, the cycle CYC2 may be classified to be a “medium” cycle. For example, the cycle CYC3 may be classified to be a “long” cycle.

The number of cycles belonging to each category may be determined and stored in the memory of the communication unit as usage data. The number of cycles belonging to each category may be determined and stored e.g. after stop time of each new operating cycle.

The maximum actual speed of rotation during the first cycle CYC1 may be e.g. equal to a value VEL2. The maximum actual speed of rotation during a different cycle CYC2 may be e.g. equal to a different value VEL1.

The symbol I_MAX may denote a maximum value of the measured driving current.

The measured operating temperature of the motor may be compared with one or more limit values TLIM1, TLIM2, TLIM3.

The symbols t_(1H), t_(2H), t_(3H), . . . t_(6H) denote times when the temperature is equal to a temperature limit TLIM1 or TLIM2.

The first limit value TLIM1 may represent a criterion for warm operation. A measured operating temperature which is lower than the limit value TLIM1 may be classified to be a normal operating temperature. The second limit value TLIM2 may represent a criterion for hot operation. A measured operating temperature which is higher than the limit value TLIM2 may be classified to be a high operating temperature. A measured operating temperature which is between the values TLIM1, TLIM2 may be classified to be a warm operating temperature. The duration in each temperature regime may be determined by analyzing the measured temperature data T_(M)(t). Temperature history data may be determined and stored as usage data e.g. when the measured temperature attains the temperature limit TLIM1 or TLIM2.

The limit value TLIM3 may indicate a maximum allowed operating temperature of the motor. The driving unit 400 may be arranged to trigger an emergency stop when the measured temperature exceeds the maximum allowed operating temperature TLIM3.

Referring to FIG. 10 a , the parameter data PAR1 may specify e.g. one or more of the following parameters: maximum allowed speed of rotation (VEL_MAX_ALLOWED), maximum allowed rate of change of the rotation speed (DVEL_MAX_ALLOWED), maximum allowed operating current (I_MAX_ALLOWED), limit value for short duration (LLIM1), limit value for long duration (LLIM2), limit value for warm operation (TLIM1), limit value for hot operation (TLIM2), and maximum allowed temperature (TLIM3).

The operating parameters PAR1 may be copied from the communication unit MOD1 into the driving unit 400. The driving unit 400 may be configured to drive the motor according to the parameter data PAR1, so as to provide optimum and/or maximum performance for the specific abrading device 200, which is connected to the driving unit 400.

The same driving unit 400 may be used together with several different abrading heads 300 during the lifetime of the driving unit 400, e.g. over a time span of several years. Using the communicating unit MOD1 may allow changing the algorithms and/or the operating parameters during the lifetime of the driving unit 400, e.g. in order to gather the usage data which is most relevant for facilitating maintenance and product development.

In an embodiment, the driving unit may be capable of driving the abrading head or an abrading device also in a situation where the communication unit is missing or in a situation where updating of the operating parameters is not successful. The driving unit 400 may be arranged to use a default set of operating parameters, e.g. in a situation where data transfer is not successful, or in a situation where new operating parameters are not available. The default set of operating parameters may be suitable for driving a specific motor and/or a specific abrading device. The default set of operating parameters may be stored in a memory of the driving unit. The default set of operating parameters may be suitable for driving most of the abrading heads connectable to the driving unit, at least at a moderate performance level. The default set of operating parameters may be suitable for driving all abrading heads of a predetermined type.

In an embodiment, the driving unit 400 may be arranged to use a previous set of operating parameters, e.g. in a situation where data transfer is not successful. In an embodiment, the value of one or more operating parameters may be changed according user input, which may be provided e.g. via the interface UIF1.

However, using the updated head-specific operating parameters PAR1 may provide optimum and/or maximum performance of the abrading head 300.

The driving unit 400 and/or the abrading head 300 may gather operating data OPDATA1. The operating data OPDATA1 may comprise measured values of operating parameters of the abrading head 300.

The operating data OPDATA1 may comprise e.g. current and temperature values measured in real time. Operating data may be determined and/or measured during operation of the abrading head 300. The initial amount of the operating data may be large and/or the operating data may be provided at a high rate. The method may comprise compressing and/or processing the operating data so as to facilitate storing and/or transfer of the operating data.

The method may comprise forming usage data by processing the operating data, e.g. in order to facilitate storing the usage data in the communication unit. The method may comprise forming the usage data in order to facilitate transferring the usage data to the communication unit. The usage data may represent relevant operating history data of the abrading head in a compressed form. The usage data USAG1 may e.g. comprise one or more values indicative of number of operating cycles, one or more values indicative of duration of operating cycles, and/or one or more values indicative of distribution of duration of operating cycles.

Referring to FIG. 10 b , the usage data USAG1 may comprise e.g. one or more of the following values: number of motor starts (N_START), number of operating cycles of short duration (N_SHORT), number of operating cycles of medium duration (N_MEDIUM), number of operating cycles of long duration (N_LONG), average speed of rotation (VEL_AVE), maximum speed or rotation (VEL_MAX), number of operating cycles representing operation in the normal temperature region of the motor (N_NORMAL), number of operating cycles representing operation in the warm temperature region of the motor, (N_WARM), number of operating cycles representing operation in the hot temperature region of the motor (N_HOT), total duration of operation in the normal temperature region of the motor (DUR_NORMAL), total duration of operation in the warm temperature region of the motor (DUR_WARM), total duration of operation in the hot temperature region of the motor (DUR_HOT), total duration of operation in the normal temperature region of the driving unit (DUR_DRV_NORMAL), total duration of operation in the warm temperature region of the driving unit (DUR_DRV_WARM), total duration of operation in the hot temperature region of the driving unit (DUR_DRV_HOT), minimum voltage level (V_MIN), average voltage level (V_AVE), maximum voltage level (V_MAX), minimum current (I_MIN), average current (I_AVE), maximum current (I_MAX), total electrical energy consumed by the motor (KWH1), maximum phase imbalance of the driving currents (DI_MAX), identifier of driving unit 400 (ID_400), identifier of abrading device 200 (ID_200), identifier of the motor MOTOR1 (ID_MOTOR1), identifier of the set of operating parameters PAR1 (ID_PAR1), identifier of program code PROG1 (ID_PROG1).

The usage data USAG1 may comprise one or more values (e.g. N_NORMAL, N_WARM, N_HOT, DUR_NORMAL, DUR_WARM, DUR_HOT) indicative of temporal distribution of operating temperature T_(M)(t). The usage data USAG1 may comprise one or more values (I_AVE, I_MAX) indicative of measured magnitude of the driving current (I_(M)(t)). The usage data USAG1 may comprise one or more values (N_SHORT, N_MEDIUM, N_LONG) indicative of distribution of duration of the operating cycles (CYC1, CYC2, . . . )

The driving unit 400 and/or the communication unit MOD1 may determine the usage data USAG1 from the measured operating data OPDATA1 according to algorithms defined by the program code PROG1 and/or according to the operating parameters PAR1.

The driving unit 400 or the communication unit MOD1 may be arranged determine a value of the end of life indicator IND1 from the operating data OPDATA1 and/or from the usage data USAG1. The driving unit 400 or the communication unit MOD1 may determine the end of life indicator IND1 according to an algorithm defined by the program code (PROG1).

For example, the total amount of energy (e.g. KWH1) consumed by the motor MOTOR1 may be used as an end of life indicator IND1. Determining an end of life indicator IND1 may comprise e.g. determining the total amount of energy consumed by the motor MOTOR1. The total energy may be determined from the measured current values. The method may comprise estimating a degree of wear of a part of the abrading head 300 by comparing the end of life indicator IND1 with a reference value. The method may comprise estimating a remaining lifetime of the abrading head 300 by comparing the end of life indicator IND1 with a reference value (e.g. 1000 kWh). For example, the remaining lifetime may be estimated to be zero when the determined end of life indicator IND1 attains the reference value.

For example, the total duration of operation at the hot temperature region (DUR_HOT) may be used as an end of life indicator IND1. The end of life indicator IND1 may be compared with reference value (e.g. 10 h). For example, the remaining lifetime may be estimated to be zero when the determined end of life indicator IND1 attains the reference value.

The end of life indicator IND1 may also be determined e.g. as a function of two or more values of the usage data USAG1.

Referring to FIG. 11 , the abrading system 500 may optionally comprise one or more auxiliary sensors TC3.

For example, system 500 may comprise an auxiliary sensor TC3 for monitoring temperature of the object OBJ1. Processing of the object OBJ1 with the abrading head 300 may generate heat. The system 500 may use information about the temperature of the object OBJ1 e.g. in order to prevent overheating the object OBJ1.

For example, system 500 may comprise an auxiliary sensor TC3 for monitoring ambient temperature of the operating environment of the abrading head 300. For example, system 500 may comprise an auxiliary sensor (TC3) for monitoring magnitude of vibration of the abrading head 300. The ambient temperature and the magnitude of vibration may have an effect on the operating life of the abrading head 300. The usage data may comprise one or more values representing history of ambient temperature. The usage data may comprise one or more values representing history of magnitude of vibration.

The one or more auxiliary sensors TC3 may send sensor data to the communicating unit MOD1, to the driving unit 400 and/or to the control system of the robot ROBO1. The sensor data may be sent e.g. via electrical cable, via an optical cable, by wireless communication and/or by wireless optical communication. The sensor data may be sent e.g. according one of the following communication protocols: 5G, Wifi, Bluetooth, ZigBee, MQTT IoT, CoAP, DDS, NFC, RFID, Z-wave, Sigfox.

The communicating unit MOD1 may optionally comprise an antenna and a transmitter-receiver-unit for enabling wireless communication COM3. The driving unit 400 may optionally comprise an antenna and a transmitter-receiver-unit for enabling wireless communication COM4.

However, communicating the data (PAR1, PROG1, USAG1) via the cable COM1 between the communication unit MOD1 and the driving unit 400, may ensure reliable operation in the industrial environment.

In an embodiment, the abrading device 200 may be arranged to cause substantially linear oscillation of the abrasive element ABR1. The abrading device 200 may comprise e.g. an electromagnetic actuator (MOTOR1) for causing substantially linear vibration of the support element PAD1 and/or the abrasive element ABR1. The driving unit 400 may provide one or more alternating currents for driving the electromagnetic actuator at a desired vibration frequency.

The communication unit MOD1 may comprise machine-readable memory for storing one or more identifiers ID_MOD1, ID_200, ID, MOTOR1. The identifiers ID_MOD1, ID_200, ID, MOTOR1 may be written to the memory of the communication unit MOD1 e.g. at a production facility (SITE4) or at a service site (SITE2). The driving unit 400 may comprise machine-readable memory for storing one or more identifiers ID_400. The identifier ID_400 may be written to the memory of the driving unit 400 e.g. a production facility (SITE4) or at a service site (SITE2). The identifier ID_PAR1 may be e.g. embedded in a data structure of the set of operating parameters PAR1. The identifier ID_PROG1 may be e.g. embedded in a data structure of the program code PROG1. The identifier ID_PAR1 may comprise information which indicates a version number. The identifier ID_PROG1 may comprise information which indicates a version number. Each identifier may be e.g. a unique code. Each identifier may be e.g. a unique serial number.

The driving unit 400 may have an identifier ID_400, which identifies a serial number of the driving unit 400 and/or a type of the driving unit 400.

The identifier ID_400 of the driving unit 400 may be copied to a memory of the communication unit MOD1 at the abrading site SITE1, so as to allow determining the serial number and/or type of the driving unit 400 after the abrading head 300 has been detached and transported to the service site SITE2.

The communication unit MOD1 may have an identifier ID_200, which identifies a serial number of the abrading device 200 and/or a type of the abrading device 200. The identifier ID_200 may be stored in a memory of the communication unit MOD1 in a machine-readable form. The driving unit 400 may comprise a memory for storing identifier data, which indicates the identifiers of the one or more communication units, which have been connected to the driving unit. The identifier data may be copied from the driving unit to a memory of a communication unit MOD1.

Sometimes an unauthorized counterfeiter may produce a counterfeit device, which may be e.g. of inferior quality or even dangerous to use. In an embodiment, the driving unit may be arranged to check whether the abrading tool is genuine or not. For example, the driving unit may be arranged to check whether the communication unit may provide a valid response to an interrogation signal. The driving unit may be arranged to prevent operation of the abrading tool in a situation where the communication unit does not respond to an interrogation signal by providing a valid response.

For the person skilled in the art, it will be clear that modifications and variations of the devices and the methods according to the present invention are perceivable. The figures are schematic. The particular embodiments described above with reference to the accompanying drawings are illustrative only and not meant to limit the scope of the invention, which is defined by the appended claims. 

1. A method for controlling operation of an abrading system, the method comprising: providing an abrading head, which comprises an abrading device and a communication unit, providing parameter data associated with the abrading device, storing the parameter data into a memory of the communication unit, transporting the abrading head to an abrading site, electrically connecting the abrading head to a driving unit at the abrading site, transferring the parameter data from the communication unit to the driving unit at the abrading site, and driving an electric motor of the abrading device with the driving unit according to the parameter data.
 2. The method of claim 1, comprising forming usage data and storing the usage data into a memory of the communication unit during operation of the abrading head, the usage data comprising information about operating history of the abrading head.
 3. The method of claim 1, comprising transporting the abrading head from the abrading site to a second site, and reading the usage data from the memory of the communication unit at the second site.
 4. The method according to claim 1, wherein the communication unit comprises program code, wherein the method comprises measuring one or more operating parameters (T_(M)(t), I_(M)(t), VEL(t)) of the abrading head during operation, and forming usage data from the measured operating parameters (T_(M)(t), I_(M)(t), VEL(t)) according to one or more algorithms defined by the program code.
 5. The method according to claim 1, wherein the communication unit comprises program code, wherein the method comprises measuring one or more operating parameters (T_(M)(t), I_(M)(t), VEL(t)) of the abrading head during operation, and determining an end of life indicator from the measured operating parameters (T_(M)(t), I_(M)(t), VEL(t)) according to an algorithm defined by the program code.
 6. The method of claim 4 comprising transferring the program code from the communication unit to the driving unit, and executing the program code by one or more data processors of the driving unit.
 7. The method according to claim 1 comprising: performing one or more service operations to the abrading device of the abrading head at the second site after reading the usage data, and transporting the abrading head to an abrading site after performing the one or more service operations.
 8. An apparatus, which comprises an abrading head, the abrading head comprising an abrading device for abrading a surface, wherein the abrading device is connectable to a stationary driving unit for driving an electric motor of the abrading device with electric currents (I₁, I₂, I₃), and wherein the abrading head further comprises a communication unit connectable to the driving unit for receiving usage data, the usage data comprising information about operating history of the abrading head.
 9. The apparatus of claim 8, wherein the abrading device is a random orbital abrading device, and wherein the abrading device comprises a synchronous electric motor.
 10. The apparatus of claim 8, wherein the apparatus is arranged to monitor one or more operating currents (I₁, I_(M)(t)) of the driving unit, and to determine the usage data based on the one or more operating currents (I₁, I_(M)(t)).
 11. The apparatus according to claim 8, wherein the apparatus is arranged to monitor operating temperature (T_(M)(t)) of the abrading head, and to determine the usage data based on the operating temperature (T_(M)(t)) of the abrading head.
 12. The apparatus according to claim 8, wherein the abrading head comprises a temperature sensor to measure an operating temperature (T_(M)(t)) of abrading head, and the temperature sensor is arranged to provide a temperature signal to the driving unit.
 13. The apparatus of claim 12, wherein the driving unit is configured to form the usage data based on the temperature signal.
 14. The apparatus according to claim 8, wherein the abrading head is attached to an actuator, the motor is connected to the driving unit, and the communication unit is connected to the driving unit.
 15. The apparatus according to claim 8, wherein the apparatus is arranged to form the usage data during operation of the driving unit, and wherein the apparatus is arranged to store the usage data in a memory of the communication unit during operation of the driving unit. 